Most electronic components are affected by changes in temperature. Resisters and capacitors, for example, change value when the temperature varies over a wide range. The tendency of a component to change in value with temperature variations is known as temperature coefficient. Thus, for resisters, there is a temperature coefficient of resistance which varies in value with temperature variations. The temperature coefficient (TC or tempcos) is usually expressed parts per million per degree Celsius (ppm/deg C).
A resistor is a circuit component that provides a fixed value of resistance in ohms to oppose the flow of electrical current. A resistor can control or limit the amount of current flowing in a circuit, provide a voltage drop in accordance with ohms law, or dissipate energy as heat. Naturally, the design of any electrical device is prefaced on the anticipation that specific components such as resisters will have properties which fluctuate in a limited and desirable amount over varied operating temperatures. For automotive electronic components, it is desirable that resistors within an electronic device have a resistance which varies within a desired range over an operating temperature ranging from -40.degree. C. to 125.degree. C.
A variety of compositions are known for making conductor and resistor films. Heretofore, it has been generally accepted that a conductor film should have good adhesion to a substrate, relatively low sheet resistivity and relatively low Pd content toe provide good solderability. However, such conductors have not been effective in controlling the TCR tracking of resistors that they are terminated to.
Thus, there is a need for systems which can limit the temperature coefficient resistance variation (known as Temperature Coefficient of Resistance tracking or TCR tracking) of resistors with respect to temperature.